Over the needle catheters are used for peripheral intravenous entry into the vasculature of a patient. The disposable medical product is packaged as an assembly of a catheter adapter with its catheter and a needle and hub assembly conjugated with the catheter adapter such that the needle passes through the catheter tube and extends a slight distance beyond the distal tip thereof to provide a sharpened point for penetration through the skin of the human or animal being catheterized. During catheterization blood flows due to the vascular blood pressure through the hollow needle and into the transparent needle hub so it is visually apparent that the tip of the needle has reached into the blood vessel. Thereafter, the needle and hub as an assembly are removed from the catheter while the practitioner places a finger against the skin of the human or animal to compress the skin and the vessel therebeneath and distal to the catheter tube and thereby prevent the flow of blood through the catheter tube, into the catheter adapter and out onto the patient and the bedding. This approach has been used and is essentially bloodless, however, with greater concern about the spread of communicable diseases, particular those such as Acquired Immune Deficiency Virus and Hepatitis which are presently incurable, a need for a better technique, one that is automatically bloodless is required.
Use of an over the needle catheter is most conveniently performed by a single handed one finger technique. In particular, the needle and catheter assemblies are concentric and conjugate when they are inserted through the skin of the human or animal and into the vasculature. Once flashback is noted in the hub of the needle, a finger is generally placed on a portion of the catheter adapter and two other fingers of the same hand, one of which may be the thumb are used to control the hub. The finger on the catheter adapter pushes toward the patient such that the catheter and its adapter as an assembly are separated from the needle and hub assembly by the use of one hand. Practitioners usually use the other hand to hold the patient's arm steady, thus comforting the patient and enabling appropriate control of the procedure. It is of value to be able to withdraw the needle and hub assembly from the catheter and adapter assembly without having to use the hand which positions the patient's arm to also press against the catheter tube and stop blood flow. In that regard, a catheter adapter which includes an integral valve to automatically prevent blood loss would be of value in that the single handed technique described could be used without concern or need for the additional hand to prevent loss of blood from the catheter adapter.
Catheter adapters with manually actuated valves are shown in U.S. Pat. Nos. 3,811,440 and 3,856,010. Those manually actuated valves require that the valve in the catheter adapter be depressed during and after withdrawal of the needle and in that way the technique is similar to depressing the vessel but for the added expense of the valve. Valves actuated by the luer fitting on a syringe, administration set or the like are shown in U.S. Pat. Nos. 4,387,879 and 4,842,591. Those valves are normally closed and the insertion of the luer fitting into the housing containing the valve compresses the valve and opens a flow path.
U.S. Pat. No. 3,831,629 discloses a two piece check valve having a sleeve like valve body and valve element reciprocal therewithin. The valve element has an elastomeric rear end portion integral therewith and held in axial compression such that it is constantly urged forward toward a valve closed position. The proximal end of the valve element is crimped radially inward to form a fluid passing abutment and means is provided to guide the valve element for reciprocation within the body and maintain its concentric relative thereto. The mechanism is complicated in that a number of pieces are required to provide the integral valve and there is no showing of the valve in connection with an over the needle catheter assembly which permits a needle to pass through the valve.
U.S. Pat. No. 4,512,766 shows an assembly and needle hub with a needle passable through a penetratable self sealing material in the assembly. A slit or puncture is provided in the proximal end of the valve member which is spread upon axial compression by the luer of a syringe or the like. The slit provides a passage for the needle and also acts as the valve. Radial tension across the slit is relied on to close the valve member.
U.S. Pat. No. 4,874,377 shows a self occluding cannula assembly. The occluding means permits withdrawal of the needle and is in the form of an aperture which is either dialated by the tapered luer of a syringe or the like or penetrated by a needle passed therethrough. The aperture is formed by beveling the outward surface of the occluding member in each direction from the aperture such that a web of material closes the aperture. The aperture is torn by the radial spread of the forced luer and is eased by the thin material of the web. Resealing the aperture formed through the web is doubtful.
U.S. Pat. No. 3,385,301 shows a balloon catheter with a deformable one way inflation valve wherein a resilient valve member is captured in one leg of a Y adapter through which a syringe may be used to collapse the valve thus opening that path to air for inflating the balloon.
U.S. Pat. No. 4,681,132 has a check valve with a pre-set cracking pressure. The resilient member in this valve is biased by a plug which can be of varying heights adjusted to account for different tolerances of the valve bodies and the like. How the plug allows the manufacture with a pre set cracking pressure of this normally closed valve is the idea of this disclosure.
The aforesaid luer activated valves do not include in their designs sufficient capability for use with luers of varying dimensions. The engagement length of luer fittings can vary as much as 2.5 mm and still be considered to meet standard specifications. A positive seal upon withdrawal of the needle during the single handed introduction of an over the needle catheter assembly is required. These luer activated valves do not provide reliable activation of an automatic valve within the catheter adapter for the intravenous catheter. The catheter adapter with a valve as shown and disclosed in the present Specification overcomes the problems of the aforesaid valves.